1. Field of the Invention
This invention relates in general to sense amplifiers and more specifically to a sense amplifier with multiple bits sharing a common reference.
2. Description of the Related Art
Sensing the state of a memory having at least two distinct resistance states, such as a magneto-resistive RAM (MRAM) requires comparison of an average signal (developed from a reference high bit and a reference low bit) with a bit cell signal. This comparison results in one data output. Typically, each data output of a MRAM module requires a pair of reference columns (one for reference high bit and the other for reference low bit). Use of a pair of reference columns for each data output increases the memory area. Moreover, each pair of reference columns consumes power, thus increasing the power consumption of the MRAM module.
Thus, there is a need for a sense amplifier with multiple bits sharing a common reference.
Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve the understanding of the embodiments of the present invention.